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arXiv 2408.03374astro-ph.GA
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ALMA-CRISTAL Survey:$z=4-6$ 恒星形成星系中 [CII] 谱线发射的空间延展

The ALMA-CRISTAL Survey: Spatial extent of [CII] line emission in star-forming galaxies at $z=4-6$

Ryota Ikeda, Ken-ichi Tadaki, Ikki Mitsuhashi, Manuel Aravena, Ilse De Looze, Natascha M. Förster Schreiber, Jorge González-López, Rodrigo Herrera-Camus, Justin… 展开作者

Ryota Ikeda, Ken-ichi Tadaki, Ikki Mitsuhashi, Manuel Aravena, Ilse De Looze, Natascha M. Förster Schreiber, Jorge González-López, Rodrigo Herrera-Camus, Justin Spilker, Loreto Barcos-Muñoz, Rebecca A. A. Bowler, Gabriela Calistro Rivera, Elisabete da Cunha, Rebecca Davies, Tanio Díaz-Santos, Andrea Ferrara, Meghana Killi, Lilian L. Lee, Juno Li, Dieter Lutz, Ana Posses, Renske Smit, Manuel Solimano, Kseniia Telikova, Hannah Übler, Sylvain Veilleux, Vicente Villanueva

AI总结:

本研究基于 ALMA-CRISTAL Survey 分析了 34 个 $z=4-6$ 恒星形成星系的 [CII] 谱线发射空间结构,发现其比连续谱更延展且符合指数轮廓,主要受恒星形成 PDR 驱动,并受原子气体等影响。

摘要:

我们研究了来自 ALMA-CRISTAL Survey 的 $z=4-6$ 处 34 个星系样本中 [CII] 谱线发射的空间延展和结构。通过对干涉可见度中的 [CII] 谱线发射进行建模,我们假设指数轮廓推导了 [CII] 谱线发射的有效半径。[CII] 谱线半径范围为 0.5 至 3.5 kpc,平均值为 $\langle R_{e,[CII]}\rangle=1.90$ kpc。我们将 [CII] 尺寸与静止系 UV 和 FIR 连续谱的尺寸进行了比较,这些尺寸分别从 HST F160W 图像和 ALMA Band-7 连续谱图像中测量得出。我们确认 [CII] 谱线发射在空间上比连续谱发射更延展,平均尺寸比为 $\langle R_{e,[CII]}/R_{e,UV}\rangle=2.90$ 和 $\langle R_{e,[CII]}/R_{e,FIR}\rangle=1.54$,尽管大约一半的 FIR 探测样本在 [CII] 谱线和 FIR 连续谱发射之间显示出相当的空间延展。最佳拟合模型的残差可见度未显示出通量过剩的统计证据,表明恒星形成星系中的 [CII] 谱线发射可以用延展的指数轮廓来表征。总体而言,我们的结果表明,[CII] 谱线发射的空间延展主要可以通过与恒星形成活动相关的 PDR 来解释,而来自弥漫中性介质(原子气体)的贡献以及过去并合事件的影响可能进一步扩大了 [CII] 谱线的分布,导致其变化。最后,我们报告了 $Σ_{[CII]}$ 与 EW$_{Lyα}$ 之间的负相关性,以及 $R_{e,[CII]}/R_{e,UV}$ 与 EW$_{Lyα}$ 之间可能的负相关性,这可能与原子气体在很大程度上贡献了延展的 [CII] 谱线发射的情景一致。未来对 Ly$α$ 和 H$α$ 谱线的 3-D 分析将有助于阐明延展的 [CII] 谱线发射与原子气体和外流之间的关联。

英文摘要:

We investigate the spatial extent and structure of the [CII] line emission in a sample of 34 galaxies at $z=4-6$ from the ALMA-CRISTAL Survey. By modeling the [CII] line emission in the interferometric visibility, we derive the effective radius of [CII] line emission assuming an exponential profile. The [CII] line radius ranges from 0.5 to 3.5 kpc with an average value of $\langle R_{e,[CII]}\rangle=1.90$ kpc. We compare the [CII] sizes with the sizes of rest-frame UV and FIR continua, which were measured from the HST F160W images and ALMA Band-7 continuum images, respectively. We confirm that the [CII] line emission is more spatially extended than the continuum emission, with average size ratios of $\langle R_{e,[CII]}/R_{e,UV}\rangle=2.90$ and $\langle R_{e,[CII]}/R_{e,FIR}\rangle=1.54$, although about half of the FIR-detected sample show comparable spatial extent between [CII] line and FIR continuum emission. The residual visibility of the best-fit model do not show statistical evidence of flux excess, indicating that the [CII] line emission in star-forming galaxies can be characterized by an extended exponential profile. Overall, our results suggest that the spatial extent of [CII] line emission can primarily be explained by PDRs associated with star formation activity, while the contribution from diffuse neutral medium (atomic gas) and the effects of past merger events may further expand the [CII] line distributions, causing their variations. Finally, we report the negative correlation between $Σ_{[CII]}$ and EW$_{Lyα}$, and possible negative correlation between $R_{e,[CII]}/R_{e,UV}$ and EW$_{Lyα}$, which may be in line with the scenario that atomic gas largely contributes to the extended [CII] line emission. Future 3-D analysis of Ly$α$ and H$α$ lines will shed light on the association of the extended [CII] line emission with atomic gas and outflows.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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